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Test Code LAB140 Urea Nitrogen (BUN), Plasma or Serum

Additional Codes


Reporting Title



Roche Diagnostics-RMH, GMC, DH, DMH, GMH, WECC, PMC, GCMH

Siemen Diagnostics- MGH, HMH, OMH, MH, SH


Useful for evaluation of kidney function.

Performing Laboratory

OhioHealth Laboratory Services-RMH,GMC,DH,DMH, MGH, GMH, HMH, WECC, PMC, OMH, MH, SH, GCMH Core Laboratories

Specimen Requirements

Collection Instructions:

1. Serum and Plasma gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.


Submit only 1 of the following specimens:




Draw blood in a gold-top serum gel tube(s). Spin down and send 1 mL of serum refrigerated.

1. A speckled-top serum gel tube (s) or a plain, red-top tube(s) is also acceptable.

2. Indicate serum on request form.

3. Label specimen appropriately (serum).


Alternate: Preferred for Siemens Users


Draw blood in a mint green-top (heparin) gel tube(s). Spin down and send 1 mL of heparinized plasma refrigerated.

Note:  1. Indicate plasma on request form.

2. Label specimen appropriately (plasma).


Specimen Stability Information

Specimen Type Temperature Time
Serum or plasma Refrigerated 7 days
  Ambient  7 days
  Frozen  12 months


Specimen Transport Temperature

Refrigerate/Ambient OK/Frozen OK

Reference Values

8-25 mg/dL

Critical value >100 mg/dL (non-dialysis patient)

Alerting category:  First instance within 1 hour (initial result only, routine on results thereafter)


Day(s) Test Set Up

Monday through Sunday; Continuously

Test Classification and CPT Coding